1. Field of the Invention
The present invention relates to a recording apparatus that performs recording on a recording sheet by a recording means.
2. Related Background Art
A conventional recording apparatus will be described with reference to FIG. 24.
In FIG. 24, reference numeral 901 indicates a recording head that performs recording by selectively discharging ink from a plurality of discharge ports. The recording head 901 is retained in position by a carriage (not shown), and reciprocates in a direction perpendicular to the conveying direction of a recording medium, thereby performing printing on the recording medium. Reference numeral 902 indicates a platen opposed to the recording head, and retains the recording medium at a printing portion.
Next, a U-turn feeding structure will be described.
Reference numeral 905 indicates a sheet feeding cassette that retains recording mediums in a stacked state, reference numeral 906 indicates a U-turn sheet feeding roller for separately conveying the recording mediums, reference numeral 910 indicates a paper guide on the inner side of a U-turn portion, reference numeral 911 indicates a paper guide on the outer side of the U-turn portion, reference numeral 907 indicates a U-turn transport roller, reference numeral 908 indicates a U-turn transport roller adapted to be driven to rotate while pressurizing the U-turn transport roller 907, reference numeral 903 indicates a transport roller pair for transporting the recording medium to a printing portion, reference numeral 913 indicates a paper guide for guiding the recording medium to the transport roller pair 903, reference numeral 904 indicates an ejection roller pair for ejecting the recording medium, and reference numeral 909 indicates an ejection tray retaining the ejected recording medium. Reference numeral 912 indicates a U-turn paper guide flapper for switching between U-turn transport and reversal transport for two-side recording.
Next, a U-turn sheet feeding operation will be described.
The recording mediums stacked in the sheet feeding cassette 905 are separately transported in the direction of the arrow M by the U-turn sheet feeding roller 906, further transported in the direction of the arrow N by the U-turn transport roller 907 and the U-turn transport roller 908, and transported in the direction of the arrow P while guided by the paper guides 910, 911, and 913. At this time, the U-turn paper guide flapper 912 moves in the direction of the arrow Q (indicated by the dashed line) to secure the U-turn transport path. Next, the recording medium is transported to the printing portion by the transport roller pair 903, and printing is effected by the recording head 901. Then, the recording medium is transported in the direction of the arrow U by the ejection roller pair 904, and ejected onto the ejection tray 909.
Next, a two-side printing structure will be described.
Reference numerals 914 and 915 indicate duplex transport rollers, reference numeral 916 indicates duplex transport rollers adapted to be driven to rotate while pressurizing the duplex transport rollers 914 and 915, reference numeral 917 indicates outer paper guides for duplex transport, reference numerals 918 and 919 indicate inner paper guides for duplex transport, and reference numeral 920 indicates a two-side paper guide flapper for switching the transport path before and after reversal in duplex transport.
Next, a two-side printing operation will be described.
Printing is performed by the recording head 901 on the recording medium fed by the U-turn sheet feeding mechanism; when the printing on the obverse side is completed, the transport roller pair 903 and the ejection roller pair 904 are reversed in rotation to transport the recording medium in the direction of the arrow R. The recording medium is further transported in the direction of the arrow S by the transport roller pair 903, and transported to a duplex transport portion. At this time, the U-turn paper guide flapper 912 moves in the direction of the arrow T, and the two-side paper guide flapper 920 moves in the direction of the arrow K, securing the transport path for the recording medium in the direction of the arrow S.
Further, the recording medium is transported by the duplex transport rollers 914 and 915 and the duplex transport rollers 916, and guided by the paper guides 917, 918, and 919 to be transported in the directions of the arrows H and I. The recording medium is transported again in the direction of the arrow P toward the transport roller pairs 903 in a reversed state. At this time, the two-side paper guide flapper 920 moves in the direction of the arrow L (indicated by the dashed line), securing the transport path after reversal. Printing is performed on the reverse side of the reversed recording medium by the recording head 1, and, when the printing is completed, the recording medium is ejected onto the ejection tray 909, thereby completing the two-side printing.
The above-described conventional example has the following problems.
Since the paper transport path is independent, mounting of the U-turn sheet feeding mechanism and the two-side printing mechanism results in an increase in the size of the apparatus main body in height direction and depth direction, thus hindering achievement of a reduction in size. Further, the provision of the independent transport mechanism leads to an increase in cost, which means the construction cannot be adopted in an inexpensive apparatus.
Further, to cope with jamming due to defective transport of a recording medium, it is necessary to provide a mechanism allowing opening of the paper guide portion; in this case also, the transport mechanism is independent, and the paper guide portion opening mechanism is also formed separately, which leads to an increase in apparatus size and cost.